how to stop history from dropping failed command?

I don't know what has changed to make bash history drop failed commands, but it has been doing it for quite some time. Guess what. I rarely want to pull back the last command and edit it if it succeeded. What's really strange is it doesn't drop all failed commands. For example, I entered `svn svn://anonsvn.kde.org' once, and it didn't put the command in my history. I entered the same command to use it as an example for this email, and it is now in the history. Anybody know what is going on here? It really bugs me! -- Regards, Steven